Spatial Trends and Health Risks of Per- and Polyfluoroalkyl Substances in San Francisco Bay Fish from 2009 to 2019

Consumption of contaminated food, especially seafood, is a key source of human perfluoroalkyl and polyfluoroalkyl substances (PFAS) exposure. Here, we examine the occurrence of PFAS in shiner surfperch (Cymatogaster aggregata), striped bass (Morone saxatilis), white croaker (Genyonemus lineatus), and seven other sport fish from San Francisco Bay, California, U.S. over a decade of monitoring to assess the potential risks from dietary exposures. In fish collected in 2009, 2014, and 2019, perfluorooctanesulfonic acid (PFOS) was predominantly detected at levels exceeding PFOS consumption advisory thresholds established in other U.S. states. The southern regions of San Francisco Bay have been especially impacted, with over 80% of samples above the strictest U.S. PFOS consumption advisory threshold set in Massachusetts (for one eight-ounce serving a week) at 3.5 ng/g (detected range: 2.0-18 ng/g ww) compared to only 8% in the other subembayments (detected range: 0.59-8.5 ng/g ww). An additional 19 PFAS were detected, with particularly elevated levels of 7:3 fluorotelomer carboxylic acid (7:3 FTCA) found in several species and sites, representing the first observations in marine fish globally. These findings indicate the need to consider a wider range of PFAS in assessing dietary exposure risks and environmental impacts.